1. Odum School of Ecology, University of Georgia, Athens, GA 30602
2. Center of Ecology of Infectious Diseases, Athens, GA 30602
3. Center for Influenza Disease & Emergence Research, Athens, GA 30602
4. Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
5. Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109
6. Center for the Study of Complex Systems, University of Michigan, Ann Arbor, MI 48109